The first thing I would do if someone walked into my shop wanting that to be repaired is to try really hard to convince them that it's not necessary

Otherwise, what Steve said. Getting color right is an expert skill that takes natural talent and years to develop. If you are wanting to DIY this then you could make an nonessential situation far far worse.

Repairing mars like that has a high probability of making it worse. Once you do that you'll likely never get past it. It is a beauty-mark in a tool that, to me, adds character. Not on the day you do it but a couple of months later you should be past it and enjoy the guitar. If you're insistent on trying to repair it, you will have to know what the finish is (contact the builder) and find someone who has some experience in finish repair. If it were mine, it would remain as is.

Those tinted classical guitar finishes often have the color layer quite near the surface, so it's extremely easy have a problem leveling a fill, resulting in a much more visible light ring around the filled area after polishing.

Leave it alone, play music. Instruments get little dings and signs of handling if they are actually in use. . .

I am unwilling to “repair” any finish issue which does not breach the finish. Even then, I will seal it but recommend against aesthetic considerations as the Noxema is more offensive that the zit. Just accept the dents.

I'm with you as I just put a similar mark on my Taylor 814 bumping into a music stand-yet I'm with everyone else who says don't worry about it. Like the old joke, you know how you were worried about the first dent in your beautiful guitar? Don't worry any more!